I dont know why there is any question as to how this system works. It is the amount of weeks you have completed. Give or take a few days. Just pay attention to what day your level increases and it will change that day of every week you complete through the 12 weeks. For me, it is day 2 of every week that my # of weeks completed goes up.
Missions have nothing to do with it. Neither do any of the things people have been saying have to do with it. It is the weeks you have completed.
I'm lvl 11 with a dot. So its NOT weeks.
I got my dot at 11. That's not an issue. You just counted incorrectly.
No, it's not. It's the amount of weeks you've completed in Multiplayer. Missions have nothing to do with it.
Why everyone keeps saying this without any proof is beyond me.
No it's NOT!
I was over a week ahead of a friend, although he kept being a level higher than me for yet another week we were playing together.
Why does everyone keep saying this?
A better question is why do YOU keep saying it's by missions? Everything I've played through has pretty much guaranteed that it's not missions.
I had a mission last night that I completed on Day 4 of the week. You know what happened? That's right, my rank DIDN'T increase. Want to know why? Yes, because my day of the week that my rank updates is the first. Every single week (I'm on week 8 right now) on this current playthrough, my rank has increased on Day 1.
It's different for everyone. Unless you have undeniable proof of it being missions (which you don't), then your argument is invalid. I have my own experiences happening multiple times AND I have an exact quote from a Naughty Dog Developer proving that it's by weeks.